Sir,
According to Section 140 (1) (iii) of Maharashtra Goods and Services Tax Act, 2017 "the registered person shall not be allowed to take credit where the said amount of credit relates to units not entitled to claim set-off under rule 79 of the Maharashtra Value Added Tax Rules, 2005 ."
You have stated that under Maharashtra value added tax developers and builders were not allowed any Set off. Therefore in view of the above provision you will not be entitled for credit of vat amount paid in last 12 months.
Under CGST Act, 2017Section 140 (1) (iii) states that "the registered person shall not be allowed to take credit where the said amount of credit relates to goods manufactured and cleared under such exemption notifications as are notified by the Government."
There is a difference between the CGST Act and Maharashtra SGST Act, 2017. As far as CENVAT credit is concerned you are not entitled to the credit provided the same is notified as not eligible. Otherwise it is allowable.